I think I have a problem with the Hydraulic Lifters on an M43TU 318i Engine. However, before I go ahead with the repairs, I wanted to check a couple of things with you experts as the problem occured at high speed (3000RPM):

1) As the issue occured at high speed, is it likely that any other damage has occured in the process ?
2) One of the spark plug electrodes were slightly bent as a result of this problem, is this likely to have any lasting damage (I have since replaced all the spark plugs)
3) If the car has been sitting for approx 1 year, is there anything else that could have happened to the car in the meantime ?